At present, billboards displayed at plenty of public spaces, such as playgrounds, airports, shopping malls, bus stations, railway stations, and casinos, typically fall into two categories, namely acrylic billboards and LED (light-emitting diode) billboards.
Acrylic billboards can be updated only by making new ones. In doing so, the owners of the acrylic billboards not only have to pay for the new acrylic billboards but also must patiently await the delivery of new acrylic billboards—production of acrylic billboards takes time.
Owners of LED billboards are never confronted with the aforesaid problems but have to incur high LED billboard maintenance costs and expect that LED billboards usually display colors and patterns which are less attractive than colors and patterns displayed on acrylic billboards, and thus LED billboards attract lookers less than acrylic billboards do in terms of the average time the lookers spend watching the billboards.
In view of the aforesaid drawbacks of acrylic billboards and LED billboards, a promising alternative is LCD (liquid crystal display) billboards. Nonetheless, conventional LCD billboards are not free of drawbacks. For example, at the aforesaid public spaces, a conventional LCD billboard typically consists of two liquid crystal displays arranged in a back-to-back manner so as to face lookers in two opposite directions concurrently. As a result, the most obvious drawback of the back-to-back LCD billboards is that they are bulky and take up much space.
The conventional LCD billboard can also come in the form of a wall mount LCD billboard. As its name suggest, it is fixed to a wall. Its inherent drawbacks include being unadjustable in angle and being impossible to face lookers in two opposite directions concurrently.
Accordingly, it is imperative to invent a liquid crystal display which is capable of facing lookers in two opposite directions concurrently, simple in structure, lightweight, thin, adjustable in angle, and conducive to changing display contents quickly and conveniently.